1. Field of the Invention
This invention relates to tunable lasers. More specifically, the invention is a tunable laser that can simultaneously produce multiple synchronized laser beams at unique wavelengths using a single laser source.
2. Description of the Related Art
High-peak pulsed laser sources are needed at various wavelengths throughout the visible and ultraviolet region. Many applications also require a pulsed laser source to be tunable. Among the applications requiring tunable lasers are remote sensing applications (e.g., remote ozone sensing), color displays, and lithography.
Although there are some lasers that can possibly address the needed spectral regions, most present serious drawbacks. For example, dye lasers can be used to produce laser wavelengths throughout much of the visible spectrum. However, the dyes have a short lifetime and must be replaced frequently. Furthermore, some of the dyes and solvents are carcinogenic thereby complicating their replacement and disposal. In addition, the high-gain and short upper laser level lifetime lasers associated with dye lasers makes it difficult for these lasers to provide good beam quality.
With respect to the ultraviolet spectrum, rare gas halogen excimer lasers provide coverage for some of this wavelength spectrum. However, the halogens corrode the laser chamber and simultaneously deplete themselves. Halogens also pose a health hazard. Still further, the short upper laser level lifetimes associated with excimer lasers require the use of high-voltage, high-current electrical discharges. These discharges cause reliability concerns and may affect other electronic instruments.